A patient with end-stage renal disease would be required to undergo hemodialysis as often as three times a week for up to four hours each time. Hemodialysis is a procedure to clean the patient's blood and remove extra fluid in the form of urine, a process carried out by our kidneys. Hemodialysis requires vascular access to the patient whereby needles are penetrated into the patient body so as to establish blood flow between the patient and a dialysis machine to carry out hemodialysis.
Hemodialysis may be performed in the hospital, a dialysis centre or at home. In the hospital and dialysis centre, vascular access is performed by trained medical professionals, such as nurses or doctors. Generally, in the hospital and dialysis centre setting, medical professionals rotate the cannulation of the blood vessel, most commonly an arteriovenous fistula, between 5-7 sites that are spaced 2-3 cm apart to distribute the trauma experienced by the arteriovenous fistula from repeated needling evenly across the vessel. This is known as “rope ladder” technique. However, this technique is not ideal as patients generally do not have that long an arteriovenous fistula to accommodate 5-7 rotation sites and the rotation sequence may not be followed strictly due to workflow challenges, leading to complications such as aneurysms, stenosis and thrombosis. In fact, as much as one third of dialysis cost goes towards managing vascular access and complications each year (Source: Mary Stuart, Startup 2011). The “buttonhole” technique is an alternative needling technique where cannulation of the arteriovenous fistula is performed consistently at the same location of the vessel wall, and via the same punctured track between the vessel and the skin. This technique has been shown to minimize pain and to disrupt the biological mechanism that causes stenosis known as neo intimal hyperplasia. The buttonhole technique has also been shown to extend arteriovenous fistula lifespan and reduce complication rate in clinical studies (Source: M. M van Loon et al., 2009). Despite its advantages, the buttonhole technique is only available for limited number of patients as this technique is difficult to execute and is usually performed blind relying heavily on experience and skill. Further, before a patient can adopt buttonhole cannulation, a scarred tracked between the arteriovenous fistula and the skin needs to be created by blind and repeated needling through the exact trajectory across the subcutaneous tissue between the skin and the arteriovenous fistula, by the same medical professional over 10-20 dialysis sessions. This further heightens the barrier and the skills for buttonhole technique to be widely adopted.
In the home environment as well, the patient or his or her family member usually lacks the experience and skill to carry the needling technique without which the risk of trauma to the patient's blood vessel would be increased due to repeated needle punctures from unsuccessful vascular access. This often compromises the safety of the patient during dialysis, lowers the lifespan of a healthy arteriovenous fistula and increase costs of the hemodialysis treatments required to treat resulting vascular access complications. The lack of medical expertise or vascular access skills at home is also a decisive hurdle for home hemodialysis technologies from being adopted.
As such, there is a need for a device and a system to lower the skill variability in administrating of needles into the patient's arteriovenous fistula using the buttonhole technique by either the medical professional or the patient himself. An invention that can achieve that would help prolong the lifespan of the arteriovenous fistula, alleviate the risk of the patient, and reduce cost of hemodialysis treatments that goes to repairing and/or treating vascular access complications resulted by needling.